Whiteness Instability

Whiteness Instability


Our textured paint, based onTiO2, PVA and vinyl chloride / ethylene copolymers changes colour after nine months. What can we do about this?

The reduction in whiteness of your textured emulsion paints would appear to be due to nothing more than a loss of the whiteness which one would expect from the total pigment volume concentration (pigment + extender) and thet ype of film-forming binder used. The whiteness observed immediately after application of the paint is, in a way, unnatural and must be due to other causes.

There could perhaps be additional brightening due not to hollow spaces filled with air, occuring in the paint film at a critical pvc, but to voids formed in some other way. The origin of these voids is to be found in the method of production of the paint, or in its type of application to the substrate. They could be produced through excessively intensive stining during dispersion, which would tend to introduce air, or a similar effect during paint application.

The solution of your problem might well be to evoid excessive stirring of the liquid paint and to apply it without too much agitation. The degree of whiteness should be checked, the aim being to keep this constant,




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